Australia/New Zealand Weed Risk Assessment adapted for Florida.

Data used for analysis published in: Gordon, D.R., D.A. Onderdonk, A.M. Fox, R.K. Stocker, and C. Gantz. 2008. Predicting Invasive in Florida using the Australian Weed Risk Assessment. Invasive Science and Management 1: 178-195.

Aira caryophyllea (silver hairgrass) Question number Question Answer Score 1.01 Is the species highly domesticated? n 0 1.02 Has the species become naturalised where grown? 1.03 Does the species have weedy races? 2.01 Species suited to Florida's USDA climate zones (0-low; 1- 2 intermediate; 2-high) 2.02 Quality of climate match data (0-low; 1-intermediate; 2-high) 2 2.03 Broad climate suitability (environmental versatility) y 1 2.04 Native or naturalized in habitats with periodic inundation n? 0 2.05 Does the species have a history of repeated introductions outside y its natural range? 3.01 Naturalized beyond native range y 0 3.02 Garden/amenity/disturbance weed n 0 3.03 Weed of agriculture y 0 3.04 Environmental weed y 0 3.05 Congeneric weed n 0 4.01 Produces spines, thorns or burrs n 0 4.02 Allelopathic n 0 4.03 Parasitic n 0 4.04 Unpalatable to grazing animals 4.05 Toxic to animals n 0 4.06 Host for recognised pests and pathogens 4.07 Causes allergies or is otherwise toxic to humans n 0 4.08 Creates a fire hazard in natural ecosystems n 0 4.09 Is a shade tolerant plant at some stage of its life cycle 4.1 Grows on infertile soils (oligotrophic, limerock, or excessively y? draining soils) 1 4.11 Climbing or smothering growth habit n 0 4.12 Forms dense thickets n 0 5.01 Aquatic n 0 5.02 Grass y 1 5.03 Nitrogen fixing woody plant n 0 5.04 Geophyte n 0 6.01 Evidence of substantial reproductive failure in native habitat 6.02 Produces viable y 1 6.03 Hybridizes naturally 6.04 Self-compatible or apomictic

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6.05 Requires specialist pollinators n 0 6.06 Reproduction by vegetative fragmentation n -1 6.07 Minimum generative time (years) 1 1 7.01 Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) 7.02 Propagules dispersed intentionally by people n -1 7.03 Propagules likely to disperse as a produce contaminant n -1 7.04 Propagules adapted to wind dispersal n -1 7.05 Propagules water dispersed n -1 7.06 Propagules bird dispersed n -1 7.07 Propagules dispersed by other animals (externally) y 1 7.08 Propagules dispersed by other animals (internally) n -1 8.01 Prolific seed production y 1 8.02 Evidence that a persistent propagule bank is formed (>1 yr) n -1 8.03 Well controlled by herbicides 8.04 Tolerates, or benefits from, mutilation or cultivation 8.05 Effective natural enemies present in Florida, or east of the continental divide Total Score 9

*Used secondary screen from: Daehler, C. C., J.L. Denslow, S. Ansari, and H. Kuo. 2004. A risk assessment Outcome Reject* system for screening out harmful invasive pest plants from Hawaii’s and other Pacific islands. Conserv. Biol. 18: 360- 368.

section # questions answered satisfy minimum? A 8 yes B 9 yes C 17 yes total 34 yes

Data collected 2006-2007

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Question number Reference Source data 1.01 no evidence of cultivation 1.02 1.03 2.01 2.02 2.03 broad native and naturalized distribution throughout Europe, Weber (2003) Invasive Plant Species of the World. Africa, Australia/New Zealand, CABI Publishing. and parts of the Americas 2.04 Stace (1997) New Flora of the British Isles, second found on dry, sandy ground in edition. Cambridge University Press, Cambridge. Britain 2.05 Wagner, Herbst, and Sohmer (1999) Manual of the flowering plants of Hawai'i. University of Hawai'i "Native to Europe, now widely Press/Bishop Museum Press, Honolulu. naturalized" 3.01 1. Wagner, Herbst, and Sohmer (1999) Manual of the flowering plants of Hawai'i. University of Hawai'i Press/Bishop Museum Press, Honolulu. 2. New 1. "Native to Europe, now Zealand Plant Conservation Network (2005) New widely naturalized" 2. fully Zealand Adventive List. naturalized in New Zealand 3.02 no evidence 3.03 Holm (1979) A Geographical Atlas of World Weeds. Present as an agricultural weed John Wiley and Sons. in Chile and New Zealand. 3.04 Considered an environmental weed in Australia - invades coastal vegetation, heath- and Weber (2003) Invasive Plant Species of the World. woodland, riparian habitats, CABI Publishing. wetlands, rock outcrops. 3.05 no evidence 4.01 Weber (2003) Invasive Plant Species of the World. CABI Publishing. no description of these traits 4.02 no evidence 4.03 Weber (2003) Invasive Plant Species of the World. CABI Publishing. no description of this 4.04 4.05 no evidence 4.06 4.07 no evidence 4.08 no evidence 4.09 4.1 "In the native range, this grass is found in forests on sandy and generally acid soils that are not Weber (2003) Invasive Plant Species of the World. too nutrient-poor, in heaths, on CABI Publishing. rocks and dunes." 4.11 USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. growth habit: graminoid 4.12 "grows in dense colonies…preventing the Weber (2003) Invasive Plant Species of the World. establishment of native plants" CABI Publishing. [but is a short grass]

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5.01 terrestrial 5.02 USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. 5.03 USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. herbaceous Poaceae 5.04 USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. an annual 6.01 6.02 Grime, Hodgson, and Hunt (1988) Comparative Plant Ecology: a Functional Approach to Common British A. caryophyllea exhibits Species. Unwin Hyman Ltd., London. seasonal regeneration by seed. 6.03 6.04 6.05 grass (likely wind-pollinated) 6.06 1. McIntyre, Lavorel, and Tremont (1995) Plant life- 1. vegetative reproduction history attributes: their relationship to disturbance absent 2. A. caryophyllea does response in herbaceous vegetation. Journal of Ecology not exhibit seasonal 83: 31-44. 2. Grime, Hodgson, and Hunt (1988) regeneration by vegetative Comparative Plant Ecology: a Functional Approach to means, or lateral vegetative Common British Species. Unwin Hyman Ltd., London. spread. 6.07 Weber (2003) Invasive Plant Species of the World. "An annual or overwintering CABI Publishing. grass" 7.01 7.02 no evidence 7.03 no evidence 7.04 1. McIntyre, Lavorel, and Tremont (1995) Plant life- history attributes: their relationship to disturbance response in herbaceous vegetation. Journal of Ecology 83: 31-44. 2. Grime, Hodgson, and Hunt (1988) 1. not listed as being dispersed Comparative Plant Ecology: a Functional Approach to by wind 2. wind not listed as an Common British Species. Unwin Hyman Ltd., London. agent of dispersal 7.05 no evidence 7.06 externally dispersed grass 7.07 1. McIntyre, Lavorel, and Tremont (1995) Plant life- history attributes: their relationship to disturbance 1. dispersal: adhesive response in herbaceous vegetation. Journal of Ecology [assumed based on 83: 31-44. 2. Grime, Hodgson, and Hunt (1988) morphology] 2. dispersal Comparative Plant Ecology: a Functional Approach to adhesive (dispersule with an Common British Species. Unwin Hyman Ltd., London. awn, or with spiny calyx teeth) 7.08 A. caryophyllea was one of the 99 most frequent species in a Spanish dehesa, but was Malo and Suarez (1995) Herbivorous mammals as seed absent from dung samples of dispersers in a Mediterranean dehesa. Oecologia 104: rabbits, fallow deer, red deer, 246-255. and cattle. 8.01 Bartolome (1979) Germination and seedling Estimated # per plant: establishment in California annual grassland. Journal of 6.8. Estimated seed Ecology 67: 273-281. production: 365 seeds/dm2

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(=36,500 seeds/m2). [possible given the number of seeds per plant???] 8.02 A. caryophyllea does not have a large bank of persistent seeds in the soil - most of seeds germinate shortly after being Grime, Hodgson, and Hunt (1988) Comparative Plant shed, with a small amount of Ecology: a Functional Approach to Common British seed persisting in the soil after Species. Unwin Hyman Ltd., London. seed has just been shed. 8.03 8.04 8.05

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